Yes they are right. 2+784
I'm pretty sure it's just 2,420.
A + C
(-5, -7) is 7 units to the left of point H
(-7, 7) is more than 7 units up and left of point H
the x axis is at (infinity, 0), being only 7 points up from point H
Hey there!
The answer to your question is 
Given:

First, we distribute the negative sign to both terms (
) This would make the
negative and the
positive, so we have:

Add them together and we get:

Have a nice day!